• Journal of Ocean Engineering and Technology
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• v.24 no.6
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• pp.103-108
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• 2010

WIG crafts are high speed vessels with the features of a dynamic supported craft. These crafts, which are predominantly lightweight and operate at substantially greater speeds than conventional craft, could not be accommodated under traditional maritime safety instruments. WIG crafts inherently possess more hazard factors than conventional ships because of their relatively high speed, lightweight, and navigational characteristics, and an accident is likely to cause damage to the ship and a high loss of life. Because WIG crafts are composed of many systems and subsystems, the safety assessment of a WIG must use a commercial software system in the design stage. This paper reviews a safety assessment process and methodology proposed by the IMO interim guideline, which were developed in view of the configuration of WIG crafts. This safety assessment system was developed to fit the WIG's safety assessment process using a reliability analysis system widely used in commercial systems. The FHA was performed on the functional hazards of systems in the conceptual design stage.

• Molecules and Cells
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• v.27 no.3
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• pp.359-363
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• 2009

Chfr, a checkpoint with FHA and RING finger domains, plays an important role in cell cycle progression and tumor suppression. Chfr possesses the E3 ubiquitin ligase activity and stimulates the formation of polyubiquitin chains by Ub-conjugating enzymes, and induces the proteasome-dependent degradation of a number of cellular proteins, including Plk1 and Aurora A. While Chfr is a nuclear protein that functions within the cell nucleus, how Chfr is localized in the nucleus has not been clearly demonstrated. Here, we show that nuclear localization of Chfr is mediated by nuclear localization signal (NLS) sequences. To reveal the signal sequences responsible for nuclear localization, a short lysine-rich stretch (KKK) at amino acid residues 257-259 was replaced with alanine, which completely abolished nuclear localization. Moreover, we show that nuclear localization of Chfr is essential for its checkpoint function but not for its stability. Thus, our results suggest that NLS-mediated nuclear localization of Chfr leads to its accumulation within the nucleus, which may be important in the regulation of Chfr activation and Chfr-mediated cellular processes, including cell cycle progression and tumor suppression.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.91-91
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• 2001

Nramp2, also known as DMT1 and DCT1, is a 12-transmembrane domain protein responsible for dietary iron uptake as well as metal ions such as lead, manganese, zinc, copper, nickel, cadmium, and cobalt. High expression of DMT1 increase lead uptake, and DMT1-dependent lead transport was H -dependent and inhibited by iron ions. The molecular mechanism of lead transport in CNS is as yet unknown. although interactions between iron and lead at the level of absorption have been known for some time. The process of lead uptake into astrocytes was not known yet. Nramp2 may mediate transport of heavy metal into astrocytes. We investigated whether Nramp2 mediate transport of lead into astrocytes. And we do whether Nramp2 was expressed highly by deprivation of iron in Astrocytes, and lead uptake into astrocytes was influenced by expression of Nramp2. Immortalized human fetal astrocyte(SV-FHA) cells were cultured in medium containing Dulbecco's modified Eagle's medium and treated with Deferoxamine. Northern blot analysis was done for determining mRNA level of DMT1 and lead uptake assay was done in incubation condition of pH 5.5 and 7.4.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2012.04a
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• pp.109-112
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• 2012

원자력발전소는 타 산업시설에 비해 화재발생 가능성이 낮으나 방사성물질 누출가능성을 최소화하기 위하여 심층방어와 다중방호 설계를 통한 안전성확보가 매우 중요하다. 이를 위해 국내에서는 화재위험도분석(FHA)과 안전정지능력분석(SSA) 및 화재 확률론적안전성분석(Fire PSA)을 수행하고 있으며, 이 중 화재 PSA는 주요 화재구역 선별, 구역별 화재발생빈도 및 기기손상확률 계산, 화재사고 경위분석 및 화재취약성 파악 등을 분석한다. 본 논문에서는 미국 원자력규제위원회(USNRC)와 전력연구소(EPRI)가 공동 연구개발한 화재 PSA 방법론인 NUREG/CR-6850 기법을 적용하여, 화재 PSA에 필요한 화재점화빈도(Fire Ignition Frequency)를 정량적으로 계산하였다. 정확한 결과값을 도출하기 위해 매크로를 이용한 프로그램인 FIFA(Fire Ignition Frequency Analyzer)를 개발하였으며, 향후 국내 원전 화재 PSA 분석업무에 유용하게 사용될 수 있을 것으로 기대된다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.1992-1999
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• 2016

The plasma process is applied to various industrial fields such as high-tech IT industry, textiles and medical. Therefore, there is increasing interest in the plasma power supply, and demand for power devices of high efficiency and high power density is increased. Plasma power supply for process must solve the arc problem, when the plasma is unstable. The output capacitor is closely related to the arc problem. If the output capacitor is smaller, the damage from the arc problem is reduced. However, the small value of the output capacitor affects the operating characteristics of the power supply. In this paper, a LLC resonant converter is adopted, because it can achieve high efficiency and power density in the plasma DC power supply. However, due to the small value of the output capacitor, the converter is operated as a LLCC resonant converter. Therefore, a gain characteristic of LLCC resonant converter is analyzed by using the FHA (First Harmonic Approximation) in plasma power supply. Simulation and experimental results are presented to verify the characteristic analysis of LLCC Resonant Converter.

• Nuclear Engineering and Technology
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• v.51 no.7
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• pp.1765-1775
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• 2019

Multiple spurious operations (MSOs) mean multiple fire induced circuit faults causing an undesired operation of one or more systems or components. The Nuclear Energy Institute (NEI) of the United States published NEI 00-01 as guidelines for solving MSOs. And this guideline includes MSO scenarios of pressurized water reactor (PWR) and boiling water reactor (BWR). Nuclear power plant operators in U.S. analyzed MSOs under MSO scenarios included in NEI 00-01 and operators of PWRs in Korea also analyzed MSOs under the scenarios of NEI 00-01. As there are no pressurized heavy water reactors (PHWRs) in the United States, MSO scenarios of PHWRs are not included in the NEI 00-01 and any feasible scenarios have not been developed. This paper developed MSO scenarios which can be applied to PHWRs by reviewing the 63 MSO scenarios included in NEI 00-01. This study found that seven scenarios out of the 63 MSO scenarios can be applied and three more scenarios need to be developed.

• Fire Science and Engineering
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• v.18 no.4
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• pp.64-71
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• 2004

This paper describes the result of the pump room fire analysis of the nuclear power plant using CFAST fire modeling code developed by NIST. The sensitivity studies are performed over the input parameters of CFAST: the constrained or unconstrained fire, Lower Oxygen Limit (LOL), Radiative Fraction (RF), and the opening ratio of the fire doors. According to the results, a pump room fire is the ventilation-controlled fire, so it is adequate that the value of LOL is 10% which is also the default value. It is anlayzed that the Radiative Fraction does not affect the temperature of the upper gas layer. It is appeared that the integrity of the cable located at the upper layer is maintained except for the safety pump at the fire area and the Conditional Core Damage Probability (CCDP) is 9.25E-07. It seems that CCDP result is more realistic and less uncertain than that of Fire Hazard Analysis (FHA).

• Journal of the Korean Society of Systems Engineering
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• v.6 no.1
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• pp.1-13
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• 2010

KC-100 is a 4 seats, single piston engine, civil aircraft whose type certificate is applied for KAS 23 (FAR 23) for the first time in Korea. Its system safety assessment and analysis have been conducted to meet the minimum safety requirement in KAS 23 and to verify the safety of equipment, system, and installation in accordance with the requirement of ${\S}$23.1309 and the guidelines in FAA AC 23.1309-1D and SAE ARP 4761. This safety assessment begins with the FHA (Functional Hazard Assessment) at aircraft and system level in preliminary design phase, and all of the safety assessment and analysis reports including the preliminary version of SSA (System Safety Assessment) have been prepared during detail design phase. The revised version of these safety reports will be approved by Airworthiness Authority through the ground and flight test phases. In this paper, the safety assessment requirement in ${\S}$23.1309, safety assessment guideline in AC 23.1309-1D, and safety assessment and analysis methods in ARP 4761 will be explained based on the application example for KC-100 development. The experience and knowledge of this system safety assessment for civil aircraft can be applied to commuter aircraft of FAR 23 class or large transport airplane of FAR 25 class.

• The Journal of Engineering Geology
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• v.22 no.3
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• pp.353-363
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• 2012

The geology of Ulleung-Do is dominated by volcanic rocks with low strength and trachytic rocks with high strength but containing vertical joints that yield easily. Consequently, rockfalls along roadcuts are a major geological hazard, with the potential to affect the ring road of Ulleung-Do. In this study, we performed three types of rockfall hazard-risk assessment on the 3-km-long section of the ring road expected to have the highest possibility of rockfall. We used a rockfall ranking sheet in a roadside landslide hazard map, the Slope Stability Inspection Manual for National Highways (Japan), and a rockfall hazard rating system for inspection from the Japan Highway Public Corporation. We also employed the evaluation criteria of 'RHRS' developed by the Federal Highway Administration (FHA). An analysis of roadcuts at 27 sites with regard to geographic and geological conditions resulted in the identification of three classes of rockfall hazard (high, medium, and low). Of note, over 74% of slopes were assessed as high- and medium-class. Finally, a rockfall hazard map of the northeast region of Ulleung-Do was produced based on the evaluation results.

• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.856-865
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• 2012

We describe the construction and immunobiological properties of a novel whooping cough vaccine candidate, in which the aroQ gene, encoding 3-dehydroquinase, was deleted by insertional inactivation using the kanamycin resistance gene cassette and allelic exchange using a Bordetella suicide vector. The aroQ B. pertussis mutant required supplementation of media to grow but failed to grow on an unsupplemented medium. The aroQ B. pertussis mutant was undetectable in the trachea and lungs of mice at days 6 and 12 post-infection, respectively. Antigen-specific antibody isotypes IgG1 and IgG2a, were produced, and cell-mediated immunity [CMI], using interleukin-2 and interferon-gamma as indirect indicators, was induced in mice vaccinated with the aroQ B. pertussis vaccine candidate, which were substantially enhanced upon second exposure to virulent B. pertussis. Interleukin-12 was also produced in the aroQ B. pertussis-vaccinated mice. On the other hand, neither IgG2a nor CMI-indicator cytokines were produced in DTaP-vaccinated mice, although the CMI-indicator cytokines became detectable post-challenge with virulent B. pertussis. Intranasal immunization with one dose of the aroQ B. pertussis mutant protected vaccinated mice against an intranasal challenge infection, with no pathogen being detected in the lungs of immunized mice by day 7 post-challenge. B. pertussis aroQ thus constitutes a safe, non-reverting, metabolite-deficient vaccine candidate that induces both humoral and cell-mediated immune responses with potential for use as a single-dose vaccine in adolescents and adults, in the first instance, with a view to disrupting the transmission cycle of whooping cough to infants and the community.